Species

Proteomic Analyses of Human Trabecular Meshwork

Summary

Abstract: [unreadable] DESCRIPTION (provided by applicant): Glaucoma refers collectively to a group of eye diseases whose molecular basis is poorly understood. Except in "normal-pressure" glaucoma, the diseases are associated with increased intraocular pressure. Increased resistance to aqueous outflow through the trabecular meshwork (TM) appears to play a key role in the onset and progression of primary open angle glaucoma (POAG). The hypothesis of the proposal is that POAG associated proteins and protein modifications contribute to blockage of aqueous outflow in the TM. Proteomic analyses of TM tissue from in vivo trabeculectomy and left over rim-tissue from cornea transplant will be pursued to determine protein differences between normal and glaucomatous donors. Liquid chromatography tandem mass spectrometry and bioinformatic methods will be used to identify POAG associated protein and protein modifications. In preliminary studies, 4-hydorxynonenal (HNE) and Argpyrimidine oxidative protein modifications appear to be more prevalent in glaucomatous tissue. Furthermore, cochlin, a protein associated with inheritable deafness, has been found only in glaucomatous tissue. Western analysis and immunohistochemistry will be used to probe for differences in protein modifications between normal and glaucomatous TM tissue and verify the prevalence of HNE modification in glaucomatous TM tissue. Western analysis and immunohistochemistry will also be used to test the hypothesis that cochlin is associated with glaucomatous trabecular meshwork plaques/mucopolysaccharide deposits. The long-term goal of this proposal is to better understand mechanisms of glaucoma pathogenesis and facilitate the development of effective therapies for limiting disease progression. [unreadable] [unreadable]

..Cochlin expression was effective in decreasing OF and increasing ASP in MOCAS, suggesting possible involvement of cochlin in IOP elevation in vivo. COCH gene delivery has potential for use in developing a glaucoma model...

..These data suggest that interference with proteasomal activity, owing to protein modification by isoLGs, could contribute to glaucoma pathophysiology by decreasing the ability of the TM to modulate outflow resistance...